Aristida from the Latin 'arista' meaning awned, alluding to the awned lemma. Obscura from Latin meaning dark, referring to the dark-coloured spikelets.

Distribution:

Found in the far north-west corner of South Australia. Also found in Western Australia, Northern Territory, Queensland and New South Wales.

Status:

Native. Common in South Australia. Common in other states.

Plant description:

Tufted perennial grass to 54cm tall with leaf blades flat to convolute, up to 15cm long and 1.5mm wide. Inflorescence loose and contracted to open, to 15cm long and almost as wide. Glumes 1-nerved unequal, the lower about two-thirds the length of the upper; aristulate, the lower c. 8 mm long, the upper c. 13.5 mm long; lemma c. 12 mm long (including the callus of c. 1 mm long); convolute, densely tuberculate-warty. Awns filiform 30-35 mm long, subequal, the laterals shorter by 1-3 mm.

Fruit type:

Dark brown with three unequal awns much longer than the base.

Seed type:

Long pale grain to 10mm long and less than 1mm wide.

Embryo type:

Lateral.

Seed collecting:

Use hands to gently strip seeds off the mature seed spike that are turning straw colour. Mature seeds will come off easily. Alternatively, you can break off the whole seed spike.

Seed cleaning:

Place the seeds/spike in a tray and leave to dry for two weeks. No further cleaning is required if only seed collected. If seed spikes collected, use hand to strip off the mature seeds. Store the seeds with a desiccant such as dried silica beads or dry rice, in an air tight container in a cool and dry place.

Seed viability:

From one collection, the seed viability was average, at 70%.

Seeds stored:

Location

No. of seeds(weight grams)

Numberof plants

Datecollected

Collection numberCollection location

Datestored

% Viability

Storagetemperature

BGA MSB

2000 (5.6 g)2000 (5.6 g)

30

18-May-2007

RJB71937North Western

1-Aug-2007

70%

-18°C

Location: BGA — the seeds are stored at the Adelaide Botanic Gardens, MSB — the seeds are stored at the Millennium Seed Bank, Kew, England.Number of plants: This is the number of plants from which the seeds were collected.Collection location: The Herbarium of South Australia's region name.% Viability: Percentage of filled healthy seeds determined by a cut test or x-ray.